The present invention generally relates to electrophotographic printing, and more particularly, to an assembly and method for cleaning toner resin from the components of a printing device.
Electrophotography is a process whereby the light image of an original representation to be copied is usually recorded in the form of a latent electrostatic image upon a photosensitive member of a printing device. The latent electrostatic image is subsequently rendered visible by application of electroscopic marking particles, known in the art as toner. The visible toner image can be either fixed directly on the photosensitive member or transferred from the photosensitive member to another support, such as a sheet of paper, with a subsequent fixing of the image thereto.
The toner is a thermoplastic resin compound and is contained in a cartridge in such printing devices as laser printers and photocopiers. The cartridge is a replaceable supply item for these printing devices. The toner is held in a reservoir in the cartridge and then transferred onto a developer roll in the printing device. The toner is then transferred onto a photoconductor in a pattern corresponding to the image to be printed. This procedure is based on a charge distribution created on the photoconductor surface.
A common problem associated with printing devices is the leakage of toner resin from the toner cartridge and/or the developer roll. Certain printing devices have multiple toner cartridges, thus multiplying the opportunity for toner resin leakage. Over time, the components of the printing device, particularly the paper-feed assembly within the device, can accumulate a significant amount of toner resin. This leads to poor print image quality, as well as the soiling of a user""s hands and clothes and contamination of the environment around the printing device.
Accordingly, there has been an on-going need to find ways to clean the accumulated toner resin leaked to the components of the printing device. Several cleaning systems have been designed in an attempt to provide a solution to the identified need. However, the procedures used to date are, in general, costly, require a maintenance call, which can be frustrating due to inherent delays, and/or fail to remove a sufficient amount of toner resin to be successfully efficient.
It is a primary object of the present invention to provide an assembly for cleaning toner resin from the components of a printing device that is provided in a kit to users of the printing device.
It is an additional object of the present invention to provide a two-part assembly for cleaning toner resin from the components of a printing device wherein a brush is manually used to wipe certain exposed components and a pad is mountable within the printing device to scrub certain inaccessible components as they move relative to the stationary pad.
It is still another object of the present invention to provide an assembly for cleaning toner resin from the components of a printing device in order to substantially eliminate print defects associated with the accumulation of toner resin leaked from the toner cartridge and/or developer roll.
Another object of the present invention is to provide an assembly for cleaning toner resin from the components of a printing device whereby a porous member is impregnated with a compound that has a strong affinity for toner resin particles.
It is a further object of the present invention to provide an assembly for cleaning toner resin from the components of a printing device that utilizes a silicone copolymer that has the consistency of a paste for attracting and holding toner resin particles upon contact therewith.
It is an additional object of the present invention to provide a method of cleaning toner resin from the components of a printing device using a two-part kit wherein each part is adaptable to abrade the components of the printing device without inflicting damage while attracting and capturing noncontained toner resin particles within the impregnated porous material.
Still another object of the present invention is to provide a method of cleaning toner resin from the components of a printing device that is inexpensive, user-friendly and effective for its purpose.
Additional objects, advantages and other novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects, and in accordance with the purpose of the present invention as described herein, a novel assembly and method for cleaning toner resin from the components of a printing device is disclosed. Testing of this assembly, as used according to the inventive method, has shown dramatic decreases, and in some cases, elimination of the print defects normally associated with leaked toner resin. The assembly is inexpensively made, easy to use and has proven the best means known to date to effectively remove toner resin from the components of a printing device.
In its broadest aspects, the assembly comprises a porous member impregnated with a silicone copolymer paste and a rigid member with a supporting base on which the porous member is mounted. A commercial embodiment of the invention takes the form of a two-part kit, wherein a first porous member is mounted to the supporting base of the first rigid member and a second porous member is mounted to the supporting base of a second rigid member.
In the preferred embodiment, the first porous member is substantially coextensive with the first rigid member in a lengthwise direction. A tab, and preferably a plurality of spaced tabs, extends from a first longitudinal side of the first rigid member. Each tab is cut along a line at its junction with the first longitudinal side of the rigid member and scored at the inner end of the cut so as to allow folding of the tab for operative positioning.
In preferred inventive kit, the second porous member extends from a first terminal edge of the second rigid member to a point intermediate along the lengthwise dimension of the second rigid member. The first and second porous members are preferably a low density polyether urethane foam.
In one of the key aspects of the inventive assembly, the silicone copolymer paste has the general formula 
wherein x represents from about 98.8 molar percent to about 99.5 molar percent, y represents from about 0.5 molar percent to about 1.2 molar percent, and R comprises from about 70% by weight to about 100% by weight of a C15-C60 alkyl group and from about 0% by weight to about 30% by weight of a C2-C14 alkyl group. With respect to the copolymer moieties, x represents preferably from about 99.0 molar percent to about 99.2 molar percent and y represents preferably from about 0.8 molar percent to about 1.2 molar percent. Most preferably, x represents about 99.0 molar percent and y represents about 1.0 molar percent.
With respect to the R group in the second silicone polymer moiety, the C2-C14 alkyl group is preferably a hexyl group. Furthermore, the C15-C60 alkyl group is preferably a C30-C45 alkyl group. Most preferably again, the C30-C45 alkyl group is a C36 alkyl group. In the inventive assembly, either of the C15-C60 alkyl group and the C2-C14 alkyl group may be halogenated, the most preferable halogen (if present) being fluorine.
The silicone copolymer in its broadest aspects has a molecular weight (weight average) in the range of from about 80,000 to about 250,000. The molecular weight is more preferably in the range from about 80,000 to about 150,000. Most preferably, the molecular weight of the silicone copolymer is about 110,000. The inventive assembly also contemplates that the silicone copolymer has a viscosity in the range from about 3000 centipoise to about 7000 centipoise at 93xc2x0 C.
The inventive method for cleaning toner resin from the components of a printing device contemplates the use of the porous member described in its broadest aspects in a manner to attract and remove noncontained toner resin. More specifically, the method is broadly performed by opening the cover of the printing device and abrading the components with the porous member. With the preferred embodiment of the two-part kit, the abrading step comprises the steps of mounting the first porous member within the printing device for stationary positioning. Subsequently, the printing device is initiated for customary motion of the internal components. Interference contact occurs during relative movement between operating components and the stationary porous member. This results in a scrubbing action by the first porous member of the inaccessible movable components within the printing device. Alternatively and/or additionally, the abrading step is performed by wiping the second porous member across exposed surfaces within the printing device.